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Chapter 3
Counter Input
Figure 3-23 shows an example of a Pulse-Width measurement using an Arm Start Trigger. Note
that if the counter is armed while the signal-to-measure is already in the active state, the counter
will wait to perform the measurement on the next full pulse after the Arm Start Trigger.
Figure 3-23.
Pulse-Width Measurement: Using the Arm Start Trigger
Other Settings
The counter measures the pulse using the Counter Timebase signal. By default, the counter
uses an onboard 100 MHz signals as the timebase. To change the timebase, use the
CI.CtrTimebaseSrc DAQmx Channel property.
You can filter noise on any PFI signal that is an input to the counter by enabling a filter. Refer
to the
section in Chapter 6,
, for more information.
If you route the same PFI signal to multiple destinations, you should enable the Synchronization
feature. Refer to Chapter 6,
, for more information.
Two-Edge Separation
In a Two-Edge Separation measurement task, the counter measures the time between two events.
The beginning event is an active edge on a first signal. The ending event is an active edge on a
second signal. Figure 3-24 shows an example of a Two-Edge Separation measurement.
Figure 3-24.
Two-Edge Separation Measurement
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